login
A263795
Number of (n+1)X(4+1) 0..1 arrays with each row and column divisible by 3, read as a binary number with top and left being the most significant bits, and rows and columns lexicographically nonincreasing
1
3, 3, 7, 7, 17, 18, 56, 66, 218, 272, 798, 1008, 2567, 3227, 7290, 9072, 18622, 22912, 43560, 52998, 94678, 113983, 193427, 230607, 374843, 442911, 694073, 813413, 1235202, 1436754, 2122943, 2452403, 3537837, 4061097, 5735701, 6545785, 9072159
OFFSET
1,1
COMMENTS
Column 4 of A263799
LINKS
FORMULA
Empirical: a(n) = a(n-1) +9*a(n-2) -9*a(n-3) -36*a(n-4) +36*a(n-5) +84*a(n-6) -84*a(n-7) -126*a(n-8) +126*a(n-9) +126*a(n-10) -126*a(n-11) -84*a(n-12) +84*a(n-13) +36*a(n-14) -36*a(n-15) -9*a(n-16) +9*a(n-17) +a(n-18) -a(n-19)
EXAMPLE
Some solutions for n=5
..1..1..0..0..0....0..0..0..0..0....1..1..1..1..0....1..1..0..0..0
..1..1..0..0..0....0..0..0..0..0....1..1..1..1..0....1..1..0..0..0
..1..1..0..0..0....0..0..0..0..0....1..1..0..0..0....1..1..0..0..0
..1..1..0..0..0....0..0..0..0..0....1..1..0..0..0....1..1..0..0..0
..1..1..0..0..0....0..0..0..0..0....0..0..1..1..0....0..0..0..0..0
..1..1..0..0..0....0..0..0..0..0....0..0..1..1..0....0..0..0..0..0
CROSSREFS
Sequence in context: A147144 A152113 A146149 * A070925 A146687 A146655
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 26 2015
STATUS
approved